The short version: Fennel collects nothing, because it sends nothing anywhere.
Nothing. There is no account, no sign in, no analytics, no advertising identifier, and no crash reporting service.
All of it is stored in the app container on your iPhone. None of it is transmitted, and the developer cannot see any of it.
What somebody eats, how their gut behaved afterwards and what their stool looked like is about as private as personal data gets. Fennel treats it that way: it is not sent to any server, not shared with any third party, not used to target anything at you, and it appears in no log line, no metric and no notification. There is no version of this app that sends it anywhere, because there is nowhere for it to go.
Fennel 1.0 keeps your diary on the phone it was logged on, and offers no sync of any kind. If sync is ever added, it will go to your own private iCloud account, it will be off until you turn it on, and this page will say so before that version ships.
A meal photo is a memory aid so you can recognise an entry later. Fennel does no photo analysis and no food recognition, on the device or anywhere else, and this is a permanent design decision rather than a feature that has not been built yet. Photos are stored with the diary entry and are not written to your photo library or uploaded.
The only network activity is Apple handling a purchase or a restore if you choose to buy Pro, and opening a source link if you tap one, which opens in your browser. That is Apple talking to Apple, and your browser talking to a public health service or journal page. Neither one sends anything about your diary.
Purchases are processed by Apple. Fennel never sees your payment details. Apple provides the app with a receipt confirming the purchase, which stays on your device.
Deleting the app removes everything, permanently, because there is no copy anywhere else. Export first if you want to keep it.
Fennel is not directed at children and collects no data from anyone.
If this policy ever changes, the change will appear here and in the app release notes. Any version of Fennel that starts sending data anywhere would be a different app to the one described here.
Fennel is made by an independent developer. Last updated 30 August 2026.